EagleTac uses the Panasonic 18650 cells. It's right on there web site.
What they don't specify is what protection circuit they use, like Orbtronic does.
Orbtronic uses the Panasonic 18650 cells for there batteries to, they also specify they use a protection circuit made by Seiko, which is very high quality.
If I had to guess, I'd also say EagleTac uses the same Seiko protection circuit.